Police submitted documents to prosecutors Monday saying the unnamed sailor violated Japan’s Narcotics and Psychotropics Control Law, said a Kanagawa Prefectural Police spokesman who declined to provide further details.

The Navy and Naval Criminal Investigative Service are cooperating with Japanese authorities in an investigation regarding “a U.S. service member's alleged involvement in drug distribution,” Yokosuka Naval Base spokesman Jim O’Donnell told Stars and Stripes Monday.

“The Navy takes any and all illegal drug use very seriously and has a zero-tolerance policy for illegal drug use, possession or distribution,” said O’Donnell, who declined provide further details because of the ongoing investigation.